well i just noticed your thread about the check engine light, i'd say get that settled first. sorry bout soundin like a jackass in the first post i just tend to do that sometimes. theres probably not That many bolt on choices for that car, but as far as a general idea... for filters, most people agree that the highest flowing (but often minimal filtering) are the mushroom shaped style (ie hks super mega flow) however i've noticed a general consenus that a very good flowing and filtering is the apex'i like the one shown in the first few pics on this page:
http://mkiv.com/techarticles/apexi_air_filter/index.html it is however a pretty expensive filter. as far as the ducting, pretty much a short ram style is designed for an intake air volume increase which is suited mostly towards top end power, like high rpm horsepower gains, probably a higher peak number. cold air intakes are generally the longer tubing which is geared towards increased air velocity and that generally helps out the the lower to mid rpm range and helps with a lower end torque numbers a little more rather than the peak hp numbers.